attempt to supply libchallenge_bypass_ristretto_ffi, to no effect

default.nix

 let
+  moreOverlays = [ (import ./oldnix/overlay.nix) ];
+
   # Read in the Niv sources
   sources = import ./nix/sources.nix { };
   # If ./nix/sources.nix file is not found run:
@@ -10,7 +12,7 @@ let
   # If haskellNix is not found run:
   #   niv add input-output-hk/haskell.nix -n haskellNix
 
-  libchallenge_bypass_ristretto_ffi = pkgs.callPackage ./oldnix/challenge-bypass-ristretto.nix { };
+  allOverlays = moreOverlays ++ haskellNix.nixpkgsArgs.overlays;
 
   # Import nixpkgs and pass the haskell.nix provided nixpkgsArgs
   pkgs = import
@@ -20,22 +22,30 @@ let
     haskellNix.sources.nixpkgs-2009
     # These arguments passed to nixpkgs, include some patches and also
     # the haskell.nix functionality itself as an overlay.
-    (haskellNix.nixpkgsArgs // {
-      overlays = haskellNix.nixpkgsArgs.overlays ++ [
-        (self: super: { inherit libchallenge_bypass_ristretto_ffi; })
-      ];
-    });
+    (haskellNix.nixpkgsArgs // { overlays = allOverlays; });
 
-
-in pkgs.haskell-nix.project {
+  hsPkgs = pkgs.haskell-nix.project {
     # 'cleanGit' cleans a source directory based on the files known by git
     src = pkgs.haskell-nix.haskellLib.cleanGit {
       name = "PaymentServer";
       src = ./.;
     };
     modules = [{
-    packages.PaymentServer.components.library.libs = pkgs.lib.mkForce [
-      libchallenge_bypass_ristretto_ffi
+      packages.PaymentServer.components.library.libs = [
+        pkgs.pkg-config
+        pkgs.libchallenge_bypass_ristretto_ffi
       ];
     }];
-}
+  };
+in
+  hsPkgs
+  # pkgs.lib.recursiveUpdate hsPkgs {
+  #   PaymentServer.setup.propagatedNativeBuildInputs = [
+  #     pkgs.pkg-config
+  #     pkgs.libchallenge_bypass_ristretto_ffi
+  #   ];
+  #   PaymentServer.components.library.propagatedNativeBuildInputs = [
+  #     pkgs.pkg-config
+  #     pkgs.libchallenge_bypass_ristretto_ffi
+  #   ];
+  # }